School uniforms: What does the research tell us?

There is little evidence that school uniforms remedy behavior problems or boost academic performance. And while uniform policies might have a slight, positive impact on school attendance, we need to consider the downside: For some kids, uniforms may have a negative effect on well-being.

young children wearing school uniforms, with girls in skirts and mary janes, and boys in trousers and lace-up shoes

Proponents have argued that school uniforms are a good thing for morale and community spirit. Some people have also claimed that uniform policies cause improvements in school attendance and academic achievement. And it’s easy to appreciate the reasoning.

If everyone wears the same thing, it might foster a sense of group identity, and help conceal socioeconomic differences between individuals. In addition, uniforms eliminate “competitive dressing,” which ought to reduce levels of conflict and distraction. As a result, kids are less likely to misbehave, and more likely to focus on learning.

These claims have intuitive appeal. But does the evidence back them up? In many cases, the answer is no.

No compelling evidence that uniforms improve a school’s social climate

“Observe a school, introduce uniforms, and then look for improvements.”

It seems like a sound approach for testing the effects of a school uniform policy. But it isn’t. Not by itself.

For example, back the 1990s, the Long Beach Unified School District in California reported substantial reductions in student criminal behavior after allowing its member schools to adopt uniform policies (Yeung 2009). But this change didn’t happen in isolation. Schools often implemented other reforms at the same time.  How can be we sure that improvements in student discipline were triggered by the wearing of uniforms? We can’t.

So while some people became convinced that uniforms were the cause of the behavioral improvements in Long Beach public schools, they shouldn’t have been. When researchers have taken a careful look at the data, they’ve found little or no evidence that uniforms had any lasting, positive effects on students (Yeung 2009; Brunsma 2006).

There was, at best, indication some middle school and high school students — particularly girl students — had slightly better attendance rates when they wore uniforms. But how much difference did it make? Just half a day more attendance over the entire school year (Gentile and Imberman 2012).

It’s not a very inspiring outcome, and a recent study — of kids attending public and private schools throughout the United States — tells a similar tale.

In this new study, Arya Ansari and his colleagues tracked the progress of more than 6300 children over time, from kindergarten to the fifth grade.

Each year, teachers provided data about children’s behavior problems and social skills. And when the kids were in the fifth grade, researchers interviewed the children directly. They asked the kids if they were experiencing symptoms of social anxiety, and if they had ever been targeted by bullies. They also asked the kids questions about social belonging. Did they feel close to their teachers? Close to their fellow students?

With this information collected, Ansari’s team performed statistical analyses to see if student behavior varied depending on a school’s uniform policy.

The outcome? When it came to teacher’s reports, there was no evidence of a link between uniforms and student behavior.

Kids who attended schools with a uniform policy were just as likely as other children to suffer from emotional problems. They experienced similar rates of depression. Similar rates of aggression, defiance, and property destruction. Children’s social skills were basically the same, regardless of whether they wore uniforms or not.

Likewise, the children themselves reported comparable experiences with social anxiety and bullying. And social belonging? That was the one area in which uniform-wearing children reported significantly different outcomes, and it didn’t favor uniforms.

Kids who were required to wear school uniforms tended to feel less close to teachers and classmates.

So — for these 6300 kids — school uniforms didn’t seem deliver any substantial psychological benefits. And that was true whether kids attended public or private schools. The single, positive outcome was a very small advantage observed for a subset of students: In low- income schools, uniforms were linked with slightly higher attendance rates — a difference amounting to less than one day over the course of the school year.

Do school uniforms reduce distractions in the classroom? Do they help kids learn?

It sounds plausible, doesn’t it? And there is evidence in support of the idea. For instance, in their large, international study of secondary schools, Chris Baumann and Hana Krskova found that students wearing school uniforms tended to listen more attentively to their teachers (Baumann and Krskova 2016).

Listening attentively to teachers is obviously a good thing. Moreover — as the researchers noted — students in this study tended to perform better in classrooms where attentiveness was the norm. So Baumann and Krskova have suggested that all schools consider adopting a uniform policy, on the grounds that it “might enhance discipline and allow for better learning” (Bauman and Krskova 2016).

But as we’ve already seen, other studies have failed to confirm the hypothesis that uniforms reduce behavior problems. And when researchers apply rigorous methods, they haven’t found any compelling evidence that uniform policies actually boost academic achievement (e.g., Hattie 2009; Gentile and Imberman 2012).

So, despite claims to the contrary, it isn’t clear that school uniforms benefit students socially or academically. And that should make us stop and reflect before imposing a uniform policy. Because it isn’t simply a question of taking a gamble on the benefits. There are also potential costs to consider.

What can go wrong with school uniforms?

We’ve already seen one possible downside. In the study led by Arya Ansari, kids who school uniforms were less likely to feel socially connected with teachers and fellow students. Why? The researchers can’t be sure. But, in this interview at Ohio State University, Ansari speculates that it might have something to do with the quashing of individuality:

“Fashion is one way that students express themselves, and that may be an important part of the school experience. When students can’t show their individuality, they may not feel like they belong as much.”

Johanna Reidy — a public health researcher based in New Zealand — has identified several additional areas for concern (Reidy 2021).

School uniform policies can create cultural conflicts, as when members of a religious group are asked to dress in a way that is inconsistent with their beliefs or practices. And gendered uniforms can present a host of difficulties. Reidy notes that girls’ uniforms tend to be more expensive. In addition, the design of girls’ uniforms may make it harder for girls to engage in athletic activities (Nathan et al 2021). And some students may object to the very idea of wearing clothing that is differentiated by gender.

Then there is the question of affordability. What if the cost of a school uniform is burdensome to low income families? This problem has been documented in countries throughout the world, including affluent countries like New Zealand, South Korea, and the United States.

And of course uniforms must serve the basic function of protecting students from the elements. In principle, well-designed uniforms  should protect kids from cold, heat, and sun-related skin damage. In reality, uniforms aren’t always well-designed (Reidy 2021).

Does this mean that school uniforms are pointless…or worse?

Definitely not. All of the studies cited here fall short of the “gold standard” of scientific research — randomized, controlled experiments. If and when researchers finally conduct such experiments, we might discover that uniforms benefit students in important ways.

But for now, it doesn’t appear that school uniforms have any direct and substantial impact on socioemotional development or academic achievement.

To date, studies support that notion that some people perceive schools as safer or more disciplined when students wear uniforms (Yeung 2009). We have the report that teens tended to listen more attentively to their teachers (Bauman and Krskova 2016). And it looks as though uniforms may increase school attendance, if only very slightly. But these observations fall short of bold claims about school morale, community spirit, and academic performance.

School officials may come up with other reasons to implement a uniform policy. But they can’t justify it on the basis of conclusive research about school climate and student achievement. If there’s a single message that arises from these studies, it’s that school uniforms aren’t likely to have much impact on either behavior problems or academic outcomes. If we really want to help students in these areas, we need to do much more than redesign their clothes.

More reading about children and schooling

For more information about ways that we can help kids excel in school, see these Parenting Science articles:

Student-teacher relationships: Why emotional support matters

Spaced learning: Why kids benefit from shorter lessons — with breaks

Choosing books for beginning readers: Sometimes less is more

Disruptive behavior problems: 12 evidence-based tips for handling aggression, defiance, and acting out

How to stop bullying in school: An evidence-based guide to interventions that work

References: The research on school uniforms

Ansari A, Shepard M, and Gottfried MA. 2022. School uniforms and student behavior: is there a link? Early Childhood Research Quarterly 58: 278.

Baumann C and Krskova H. 2016. School Discipline, School Uniforms and Academic Performance. In Int J Educ Manag 30(6):  1003–29.

Brunsma  D L. 2006.Uniforms in public schools: A decade of research and debate. Lanham, MD: Rowman & Littlefield Education.

Gentile E and Imberman SA. 2012. Dressed for success? The effect of school uniforms on student achievement and behavior.  Journal of Economics  71: 1-17.

Hattie J. 2009. Visible Learning: A Synthesis of over 800 Meta-Analyses Relating to Achievement. Routledge.

Nathan N, McCarthy N, Hope K, Sutherland R, Lecathelinais C, Hall A, Lane C, Trost S, Yoong SL, Wolfenden L. 2021. The impact of school uniforms on primary school student’s physical activity at school: outcomes of a cluster randomized controlled trial. Int J Behav Nutr Phys Act. 18(1):17.

Reidy J. 2021. Reviewing School Uniform through a Public Health Lens: Evidence about the Impacts of School Uniform on Education and Health. Public Health Rev. 42:1604212.

Yeung R. 2009. Are School Uniforms a Good Fit? Educ Pol. 23(6):847–74.

Content last modified 1/5/2022